Register quick diff provider

Fixes #392

package.json

@@ -19,7 +19,8 @@
 		"contribCommentThreadAdditionalMenu",
 		"codiconDecoration",
 		"diffCommand",
-		"contribCommentEditorActionsMenu"
+		"contribCommentEditorActionsMenu",
+		"quickDiffProvider"
 	],
 	"version": "0.56.0",
 	"publisher": "GitHub",

src/@types/vscode.proposed.quickdiffProvider.d.ts

@@ -0,0 +1,13 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+declare module 'vscode' {
+
+	// https://github.com/microsoft/vscode/issues/169012
+
+	export namespace window {
+		export function registerQuickDiffProvider(quickDiffProvider: QuickDiffProvider, label: string, rootUri?: Uri): Thenable<Disposable>;
+	}
+}

src/view/reviewManager.ts

@@ -99,6 +99,7 @@ export class ReviewManager {
 
 		this.updateState(true);
 		this.pollForStatusChange();
+		this.registerQuickDiff();
 	}
 
 	private registerListeners(): void {
@@ -170,6 +171,17 @@ export class ReviewManager {
 		GitHubCreatePullRequestLinkProvider.registerProvider(this._disposables, this, this._folderRepoManager);
 	}
 
+	private registerQuickDiff() {
+		vscode.window.registerQuickDiffProvider({
+			provideOriginalResource: (uri: vscode.Uri) => {
+				const changeNode = this.reviewModel.localFileChanges.find(changeNode => changeNode.changeModel.filePath.toString() === uri.toString());
+				if (changeNode) {
+					return changeNode.changeModel.parentFilePath;
+				}
+			}
+		}, 'GitHub Pull Request', this.repository.rootUri);
+	}
+
 	get statusBarItem() {
 		if (!this._statusBarItem) {
 			this._statusBarItem = vscode.window.createStatusBarItem('github.pullrequest.status', vscode.StatusBarAlignment.Left);